Blindness is commonly seen in the following conditions: 1. Cataract, clouding of the lens, weakening of the refractive medium transmission, and significant loss of vision. If the vision loss has affected daily life, cataract extraction and combined IOL implantation is recommended.2. Vitreous blood accumulation, thick blood accumulation blocks light from entering the eye, resulting in severe vision loss, most commonly seen in diabetic retinopathy and retinal vein occlusion, etc. If conservative treatment is ineffective, vitrectomy is required. If conservative treatment is ineffective, vitrectomy is required.3. Central retinal artery blockage, the artery is thin or white line, embolus can be seen in the lumen, acute ischemia and hypoxia of the retina, gray edema, impaired function of the optic rod and optic cone cells, and a sharp decline in visual acuity. This is one of the common emergencies in ophthalmology, which requires urgent rescue, and the main measures include oxygen, sublingual nitroglycerin, lowering intraocular pressure, massaging the eyeball, thrombolysis, and so on.